Edmond Chow will discuss how to use our newly installed Dektak stylus profile to measure: surface roughness, film stress and step height. Practical examples in evaluating the increase of surface roughness due to different process steps such as PECVD deposition and ICP etching will be discussed. I will also discuss how to use 3D mapping feature for estimating defect density on the surface. Film stress measurement on STS PECVD silicon nitride film will be reported with data obtained from our FSM measurement system. Fully automated step height measurement with automatic step detection will be demonstrated in the livedemo at the end.